FILE -- Sen. Kamala Harris (D-Calif.) listens during a Senate Judiciary Committee hearing in Washington on Dec. 12, 2018. The 2020 presidential race is expected to draw several women and nonwhite contenders like Harris. (Sarah Silbiger/The New York Times)

Photo: Sarah Silbiger / New York Times

Word is California Sen. Kamala Harris will announce she’s running for president either on or shortly after the upcoming Martin Luther King weekend.

The exact date is still being worked out, but sources tell us it’s going to be sometime this month — the MLK holiday is Jan. 21.

“Right now, she is on a book tour, which to me looks like an unconventional run-up to an announcement,” said former political consultant Bob Shrum, who is now director of the Jesse M. Unruh Institute of Politics at the University of Southern California. As part of that tour for her new book, “The Truths We Hold: An American Journey,” Harris will appear at the Curran Theatre in San Francisco Saturday.

While the presidential primaries and caucuses are still more than a year out, those in the know say Harris needs to be up and running during the first quarter of the year or risk being lost in the herd of Democratic candidates already lining up for the 2020 marathon.

“Running for president is all about the perception of momentum,” University of San Francisco political science Professor James Taylor said. “Right now, Sen. Bernie Sanders and former Vice President Joe Biden are the only candidates with double digit support in national polls.

“Harris is well known in California, but she and the other candidates are still in the single digits nationally,” Taylor said.

Adding to the time squeeze was Massachusetts Sen. Elizabeth Warren’s announcement last week that she was forming a presidential exploratory committee.

A source involved in national Democratic fundraising said the Harris camp has already made calls to various key donor groups — the goal is to raise upward of $500,000 by March. Both Taylor and Shrum, however, said launching a successful online small- donor network is just as important as showing you can bring in the big bucks.

“Small-dollar donations are important to project a popular base of support,” Taylor said. Sanders demonstrated that during the 2016 presidential campaign.

Although Harris will have a strong campaign presence in California, her team wants its national campaign headquarters to be on the East Coast. One reason is that the national cable news outlets, which have become increasingly critical to presidential campaign exposure, all operate on Eastern Time.

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There’s also a travel advantage. With the exception of Nevada, most of the first-round Democratic caucuses and primaries are either on the East Coast or in Midwest.

Team Harris wants to be able to fly in and out of various states on short notice. They are looking for a city with quick access to airports with regular flights to California, Iowa, New Hampshire, South Carolina and other early primary states — that would let Harris continue to hold down her day job in the Senate.

The city that most closely fits the bill is Baltimore, which is near Washington but distant enough to furnish an outsider image. It also has access to three major airports.

Wherever the headquarters is located, chances are it won’t be a repeat of the heavily staffed command center that Hillary Clinton set up in New York for her 2016 campaign.

“This one will be more like a floating flotilla that moves quickly,” said one source close to the campaign.

Housewarming: The family and friends party at the governor’s mansion in Sacramento Monday night was the hottest ticket of Gavin Newsom’s inaugural.

Gavin Newsom during his inauguration ceremony as California’s 40th governor, alongside his wife, Jennifer Siebel Newsom, and their children, at the State Capitol in Sacramento.

Photo: Jim Wilson / New York Times

Michael Franti provided the live music. Alice Waters of Chez Panisse did the cooking.

Family included Newsom’s sister, Hilary Callan, and her husband, Geoff Callan; and relatives of Newsom’s wife, Jennifer Siebel Newsom.

Friends included San Francisco Mayor London Breed, San Francisco real estate magnate Clint Reilly, Newsom’s former mayoral spokesman, Nathan Ballard, and his former mayoral chief of staff, Steve Kawa.

The governor’s mansion in Sacramento — new home of Gov. Gavin Newsom and his family.

Photo: Rich Pedroncelli / Associated Press

The new governor and family stayed at the mansion that night, and the Newsom kids had friends there for a sleepover.

Newsom quipped that outgoing Gov. Jerry Brown was still moving out that morning.

“We are not completely moved in,” he said. “Most of my stuff is still outside in the car.”

San Francisco Chronicle columnist Phillip Matier appears Sundays and Wednesdays. Matier can be seen on the KPIX-TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call 415-777-8815, or email pmatier@sfchronicle.com. Twitter: @philmatier

Whether writing about politics or personalities, Phil Matier has informed and entertained readers for more than two decades about the always fascinating Bay Area and beyond. The blend of scoops, insights and investigative reporting can be found every Sunday, Monday and Wednesday in the Chronicle.